South of the pagoda courtyard is the monumental ubosot (ordination hall) of the temple. Built in 1628, the hall is a masterpiece of the Ayutthaya style. The steeply slanted columns around the exterior create a forced perspective, making the building look taller than it really is. While not unusual in Thai temples of the period, this is perhaps the best and most successful example. The columns spring from elegant inverted lotus-bud bases finished in gold and blue mirrored tiles.